Novel design for arc chamber applied to Molded Case Circuit Breakers

The aim of this project is to evaluate a novel design in arc chamber for MCCB. This proposed design is focused on the movement of the generated gas at open arcing contact event during circuit breaker operation. Normally, the arc chamber should cool the formed arc during break operation and divide the arc in smaller ones, combined with arc movement due to magnetic forces. The current design allows cooling the arc by movement, but having the risk of re-ignition because the conductive particles interact with the formed plasma. The proposed design includes a variation in the space between the splitting metal plates of the arc chamber, having an unequal space between it, producing an increase in the mobility of the gas out of the device. The obtained results from all test sequences, following the UL 489 standard, corroborates the efficacy of the novel design, by decreasing values as arc duration, arc voltage and current peak during the sequences. Also, results were compared with a mathematical simulation obtained with ANSYS software, where following the finite element model, it was possible to obtain a graphical description of the gas exhaust of the device under atmospheric conditions.